1. Field of the Invention
The present invention relates generally to an electronic device, and more particularly, to an antenna device configured to implement wireless communication functionality and an electronic device having the antenna device.
2. Description of the Related Art
Wireless communication technologies have recently been implemented in various manners including a Wireless Local Area Network (WLAN) implemented mainly by Wireless Fidelity (WiFi), Bluetooth, Near Field Communication (NFC), and the like, as well as to provide access to commercialized mobile communication networks. As mobile communication networks have evolved from the 1st Generation (1G) focusing on voice calls to the 4th Generation (4G), mobile communication services now enable provisioning of the Internet and multimedia services. It is expected that a future-generation commercialized mobile communication service will be provided in an ultra high frequency band of tens of GHz or higher.
To meet the demand for wireless data traffic which has increased since the deployment of 4th-Generation (4G) communication systems, efforts have been made to develop an improved 5th-Generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a “Beyond 4G Network” or a “Post LTE System.”
The 5G communication system is considered to be implemented in higher frequency (e.g. mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, beamforming, massive Multiple-Input Multiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, analog beam forming, and large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, Device-to-Device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid Frequency Shift Keying FSK and Feher's Quadrature Amplitude Modulation (FQAM) and Sliding Window Superposition Coding (SWSC) as an Advanced Coding Modulation (ACM), and Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) as an advanced access technology have been developed.
As communication standards such as WLAN and Bluetooth have become more prominent, an electronic device, for example, a mobile communication terminal, is equipped with an antenna device operating in various frequency bands. For example, a 4G mobile communication service is provided in frequency bands of 700 MHz, 1.8 GHz, and 2.1 GHz, WiFi is implemented in frequency bands of 2.4 GHz and 5 GHz although the frequency bands are different according to the communication standards, and Bluetooth is implemented in a frequency band of 2.45 GHz.
Commercialized electronic devices such as a TV and a large-sized electronic device have larger screens due to the scale-down of the bezel areas. As a bezel area gets smaller, a screen gets larger for a small-sized electronic device like a portable terminal. To provide a stable service quality at higher data rates in a commercialized wireless communication network, while enabling wireless communication with various external devices, an antenna device of an electronic device should provide a high gain and a wide beam coverage. Considering that a future-generation mobile communication service will be provided in a high frequency band of tens of GHz or higher, higher performance may be required for an antenna device than an antenna device used for a legacy commercial mobile communication service. For example, although a radio signal in a higher frequency band can deliver a larger amount of information faster, the radio signal may be reflected from or blocked by an obstacle and has a shorter propagation distance, because as the frequency band becomes higher, the radio signal becomes more linear.
If a plurality of antenna modules is installed, wireless signals may be transmitted and received in various frequency bands. However, the number of installed antenna modules is limited due to a limited installation space of the antenna modules. Particularly, it is difficult to secure a mounting space and position for ensuring stable performance for antenna modules in a portable small-sized electronic device with a reduced bezel area.
FIG. 1 illustrates electronic devices each having an antenna device, FIG. 2 is a schematic view illustrating the numbers of antenna devices in electronic devices and radio frequency states according to the numbers of antenna devices, and FIG. 3 is a graph illustrating data transmission capacity or channel capacity according to the number of antenna devices in an electronic device.
Referring to FIGS. 1A-1C, 2, and 3, each electronic device 10 is equipped with at least one antenna device for transmitting data to and receiving data from external devices. Currently, when the electronic device 10 is provided with a display 30, the antenna device is installed in a part of the periphery of the display 30 called a Bezel Area (BA) 20 to thereby prevent the display 30 from degrading the radiation performance of the antenna device. In contrast, if the electronic device 10 is a large-sized TV, the antenna device is installed in the BA 20 of the electronic device 10, but in the rear surface of the electronic device 10. If the electronic device 10 is a TV used at a fixed position and the antenna device is mounted on the rear surface of the electronic device 10, radio waves of the antenna device are reflected from or absorbed into a wall or the like behind the rear surface of the electronic device 10, thus degrading transmission and reception performance.
If the electronic device 10 is a portable terminal, the antenna device is provided in BAs 20 defined at the top and bottom parts of the display 30. However, like a TV, as the display 30 occupies more area of the electronic device 10, the BAs 20 become smaller. As a result, the mounting space of the antenna device is reduced, as illustrated in FIG. 1.
In addition, the electronic device 10 such as a TV or a portable terminal has recently been equipped with a plurality of antenna devices to conduct wireless communication in various communication schemes and transmit data to and receive data from an external device quickly in various radio frequencies.
Wireless communication is conducted using one antenna device in Single Input Single Output (SISO), a plurality of antenna devices at a transmitter and a single antenna device at a receiver in Multiple Input Single Output (MISO), or a plurality of antenna devices at each of a transmitter and a receiver in Multiple Input Multiple Output (MIMO), depending on the numbers of antenna devices deployed at a transmitter and a receiver, as illustrated in FIG. 2. It may be noted from FIG. 3 that the data rate of an electronic device having a MIMO antenna device, that is, more antenna devices, is increased.
As described above, the size and shape of the electronic device 10 are designed in a manner that limits the mounting space and position of the antenna device. Nonetheless, the electronic device 10 is required to transmit increasing amounts of data more quickly.
There is a need for an antenna device having a high gain and a wide radiation coverage in a future-generation wireless communication service, as stated above. Also, along with the trend of increasing screen sizes, the installation space of an antenna device configured to radiate signals forward is getting smaller. When the antenna device is installed at a different position, it is difficult to secure antenna radiation performance.
Moreover, it is difficult for antenna devices to provide stable transmission and reception performance in an ultra high frequency band in an electronic device equipped with various antenna devices operating by WiFi, Bluetooth, NFC, and the like, as well as by mobile communication.